Service Providers (SPs) generate contractually repeating revenues for the services delivered to their customers over a network. The network of a service provider includes a variety of core and edge network devices, where the core devices forward packets to only to core and edge devices in the network, and edge devices route packets between the core and other outside networks. Core devices are controlled by operating systems to route, monitor and analyze traffic to ensure that services are provided at their appropriate service levels.
Each SP supports a variety of network services, such as Domain Name Services (DNS), call services, Voice over IP, email, DHCP, etc. Network services may be provided via network trunk or tunnels across the SP network.
The underlying technology of the core and edge devices impacts the ability of the service provider to deliver services to customers. Conventional telecommunications service providers have used leased land-lines to provide circuit connectivity to customers. Circuit connectivity enables strong service level agreements to be supported because the end points and paths of the circuit are well defined. As customer demand for increased bandwidth and mobility at reduced cost has increased, however, the technology of the core and edge network resources continues to evolve in the direction of a packet-based infrastructure.
The evolution of technology towards a packet based infrastructure has challenged the service provider's ability to maintain the quality of services that is available in a circuit based network. One problem with packet-based infrastructures is the difficulty in tracing packets through a packet-based infrastructure. The decrease in packet traceability makes it difficult to pin point the location of the source of a communication packet at the core and the path which the packet takes through the infrastructure.
The ability to identify both the location of a source of a packet and the location of resources used by a client of the service provider is critical to emergency service and lawful intercept applications. Emergency services such as 911 and Enhanced 911 (E911) are designed to quickly link those requesting aid with resources capable of providing that aid. The location of the person requesting aid is required to enable service providers to identify and dispatch available resources. Lawful Intercept is a security process in which a network operator or service provider gives law enforcement officials access to the communications of private individuals or organizations. Lawful Intercept therefore requires the ability to identify the location of network resources used during communications by the client.
In traditional land-line based telecommunication infrastructures the location of a client and resources used by that client is readily available. Circuit-based infrastructure for traditional land-line phone service using Digital Signal-1 (DS-1) and Digital Signal-0 (DS-0) circuits is deterministic and has identifiers tied to the physical location of the circuit end-point. For example, referring now to FIG. 1 a circuit based network 100 such as that used in traditional digital land-line communications is shown to include a Service OSS 102 and a Network OSS 104. The Service OSS and Network OSS together map network resources to network connections to service the connections. Each OSS performs many network management tasks including inventory, provisioning system, performance monitoring system and a billing.
Customers of the service provider are assigned Common Language Location Identifiers (CLLI). The service provider uses client CLLIs to identify resources for building connections between the clients, and thus the CLLIs identify endpoints of circuit connections. Service providers maintain tables that correlate end-points to circuits. Representative tables 22 and 24 are shown in FIG. 1. When a service order is received from a customer, the OSS translates the service order into a work order for the network OSS. The network OSS designs a circuit for the service, assigning network elements and interfaces to different aspects of the service, using an existing inventory. Network resources include Common Language Equipment Identifiers (CLEIs) which uniquely identify the network equipment. Each circuit therefore includes both CLLI information, identifying the endpoints, and CLEI information identifying resources that support the circuit. Endpoint information is stored in tables (such as table 22) for each circuit. For example table 22 stores the Network Element IDs and Interface IDs (IFIDs) [or Attachment IDs (AIDs)] for each endpoint. A table 24 of core elements that are traversed by the circuit (and the associated AID at each core) is also maintained.
The table at the edge and core allow the 911 operator to match a location and circuit together and enable E911 service. For example, when an emergency service request is initiated by a customer, the location of the customer can be readily obtained by using the customer ID to locate circuit IDs and CLEIs for the customer, rapidly pinpointing customer location. The database is relatively accurate, although intermittent updates of new addresses may result in database inaccuracies at various points in time. When it is desired to lawfully intercept communications of a user, all of the circuits associated with the user, as well as the equipment and interfaces used to form the circuit, can be easily identified and passed to law enforcement to allow them to select desired locations in the circuit for taps.
With the advent of packet infrastructure and the move away from circuits it has become more difficult to link a client packet and a location of origin. When emergency service requests are initiated via internet communication devices (such as cell phones, PDAs, and other wireless devices), via Internet communication services (such as Voice over IP), the location of the individual is difficult to obtain. One reason for this difficulty is that clients which communicate via the Internet use Internet Protocol (IP) addresses that are dynamically assigned (with DHCP); thus the address of a client may differ each time it connects to the internet. Many networks which implement protocols such as MPLS or stacked-VLAN (QinQ) networks swap header packets at each hop along the path from the user to the core network, and make tracing the path back to the user almost impossible. The difficulty in determining the location of origin of a packet frustrates a service provider's ability to provide emergency services with accuracy.
It is also difficult to associate network resources with communications of a particular client due to dynamic routing of packets in the IP infrastructure. Thus packets from a source may be routed over many possible routes to the same destination. The inability to identify the particular route associated with client communications complicates a service provider's ability to provide lawful intercept.
For example, FIGS. 2A and 2B illustrate respective information flow between edge devices and the core in respective traditional leased land-line infrastructures and packet based infrastructures. The communication includes both service related information 200 and network related information 202. The information may be in the form of headers. As shown in FIG. 2A, when a communication from an edge device in a traditional circuit based network maintains consistent information from the edge to the core. Thus communications at the core in a circuit based network will include service related information 204 as well as network related information 206.
FIG. 2B illustrates the flow of information between an edge device and the network core in a packet based telecommunications infrastructure. As shown in FIG. 2B, the network information 212 may not be preserved as it travels through the core; rather intermediate nodes may perform label swapping, dynamic routing and other header processing protocols which makes it difficult to track the origination of a packet 215 at the core.
In addition to the above problems associated with locating customers, clients of emergency services typically have to be routed through multiple service providers before gaining access to the 911 operator. With the nomadic nature of the mobile device user, an internet connection may be made from any location with internet access. Because the exact location where internet access is obtained by the client is not easily accessible location determinations are prone to error and response time is delayed. Emergency service requests have been routed to service providers which are geographically distant from the person in need and unable to provide timely, if any, assistance. Delays in response time and inaccuracy of address database poses significant problems when seeking to provide accurate and timely E911 services. It is therefore desirable to identify a system for quickly ascertaining the location of clients communicating with an emergency service via the internet. It is further desirable to identify a system which would permit the location of network resources that are used by a client for communication to be identified for lawful intercept purposes.